OF NATURAL HISTORY. 277 



ir.ary caufe, which muft remain forever concealed from human pe- 

 netration. 



In moft animals, except the human fpecies, parental and filial af- 

 fedion ceafe whenever the young are able to provide for themfelves. 

 The pleafures derived from fucking, and from other circumftances 

 formerly mentioned, might for fome time remain ; but the young 

 grow large, unwieldy, petulant, and enter into competitions for food, 

 which not only contribute to alienate tlve affedion of the parents, 

 but even to excite refentment ,and averfion. Thefe, however, are 

 only fecondary caufes. The purpofes of Nature are fulfilled. The 

 ardour of affedion, which was indifpenfably neceflary to the pro- 

 teflion and rearing of the young, being now no longer ufeful, is fo 

 totally extinguifhed, that neither the parents nor the offspring are ' 

 capable of recognizing one another. This temporary and amiable 

 inftindt is obliterated, and never revives till the fervours of love are 

 again felt, and a new progeny appear. 



TVIarriage or pairing, though by no means an univerfal inftitution 

 of Nature, is not unfrequently exhibited in the animal creation. 

 With regard to man, both male and female are inftindively impelled 

 ,to make a feledion. The force of this natural impulfe is ftrongly 

 felt by every young and uncorrupted individual. When not re- 

 ftrained by neceffity, or other powerful motives, men and women 

 would intermarry long before it would be prudent in civilized or 

 .artificial ftates of fociety. This univerfal, and almoft irrefiftible im- 

 pulfe of feledtion, is to me the Itrongefl; argument in favour of mo- 

 nogamy, or the union of pairs, among the human fpecies. 



The fame impulfe, or law of Nature, takes place among many 

 other animals, as the patridge tribes, the fwallow, the linnet, and, in 



general, 



